subdominant

The subdominant is scale degree 4 of a key: the pitch a perfect fourth above the tonic (equivalently a perfect fifth below it — hence 'subdominant', the degree below the dominant), and the bearer of the subdominant function: the departure function of tonal harmony, the area of tonal motion that leaves the tonic and returns to it through the dominant. PARAMETERS: (1) intervallic status — the subdominant is the fourth degree of the key's scale, a perfect fourth above the tonic (in C major, F); (2) functional role — in Riemann's functional system the subdominant function is the area of departure from the tonic: in major it comprises the IV triad and the ii triad, in minor the iv and its kin, and it prepares the dominant's tension so that the return to the tonic is felt as resolution — subdominant → dominant → tonic is the basic cell of phrase structure; (3) scale context — in major keys the subdominant triad is major (IV); in minor keys the natural-minor subdominant is minor (iv), and the raised fourth (IV, from the melodic minor) appears in cadential practice; (4) relational definition — the subdominant is defined relative to the key and its tonic (the subdominant of C major is F), and in circle-of-fifths terms it sits one step of motion from the tonic in the direction opposite the dominant. PERSISTENCE: codified in Western tonal and harmonic theory — from the medieval eight-mode system, in which the mode a fifth below the final is named the subdominant, through Riemann's functional system (late 19th c.) to modern Roman-numeral analysis, where IV and ii are read as the departure chords; taught in harmony, counterpoint, and music-theory curricula; re-instantiated in every functional analysis (pre-dominant motion, cadence analysis); maintained through the conventions of tonal notation. Distinctions: from the dominant (degree 5 — the tension function pulling toward the tonic; the subdominant is the departure function, the dominant's circle-of-fifths neighbor on the other side of the tonic); from the subtonic (the natural-minor seventh degree, a whole tone below the tonic — a different ordinal slot; the name adjacency is a residue of mode naming, and the two degrees carry no shared function); from the solfège syllable fa (the movable-do label attached to this degree in pedagogy — a name for the degree, not the degree itself); from the IV chord (the triad built on the fourth degree — a chord built ON the subdominant, not the degree and function itself); and from a bare pitch (any point on the pitch axis; the subdominant is a pitch bearing the specific fourth-degree status and the departure function). [formal: subdominans | substrate: mind | horizon: centuries | explicit: yes | epoch: 0.01]